A conventional wireless headset is typically designed to playback music without having to interface with other applications. However, due to advent of Bluetooth technology and its wide application in mobile phones as a hands-free solution, a wireless headset can be designed with dual functions: to listen to high quality music and at the same time to be able to receive incoming calls from and input outgoing calls to a mobile phone as well as inter-communication among headsets.
When a wireless headset has the capacities of receiving incoming calls and inputting outgoing calls, it is generally attached with a boom microphone. While such design provides a voice input channel to the headset, the “boom” of the microphone imposes an awkward ID issue to the overall appearance of the headset. In addition, the design of “boom” microphone normally involves movable mechanical parts; this affects the durability of the headset and the manufacturing cost.
It is possible to eliminate the use of “boom” design by embedding the microphone into the housing of a headset. However, due to close proximity between the embedded microphone and headset speaker, echo from the headset speaker will be picked up by the embedded microphone due to acoustic coupling, thus making the headset impractical for communication without echo-cancellation.
Another major problem for microphones in a wireless headset is that the microphones can pick up ambient noises so that the quality of voices is impaired by the ambient noises. For example, wind flow over a microphone will induce significant amounts of low frequency noise. U.S. Pat. App. 2006/0034476 A1 discloses a wireless communication headset for reducing wind-induced noise by disposing the microphone in a cavity of the headset, but the headset is bulky because the microphone portion is protruded from the speaker portion.
Yet another problem of a headset with embedded microphone is the low signal to noise ratio (SNR) because the distance of microphone is farther away for the mouth position, thus affecting the speech quality for communication. Since the coding/decoding process through mobile phone network requires good speech signal at the input, the quality of speech signal becomes critical for the headset with embedded microphone.
Therefore, there is an imperative need of providing a wireless headset with echo control and noise cancellation. The present invention satisfies all the requirements by providing a headset that has embedded microphones, where the embedded microphones have such configurations that the echoes from the speakers are well controlled and the noises from the ambient environment are minimized if not completely eliminated. Other advantages are apparent in view of the detailed description hereinafter.